The small North Wales town of Llangollen is situated on the A5 by the river Dee and on the edge of the Berwyn mountains, and has a wealth of shops, cafes, bars, restaurants and places to stay. Just out of the town centre is Plas Newydd country house which was home to the Ladies of Llangollen during the late 18th/early 19th century, and which still has many of the Gothic features they introduced; the gardens surrounding the house are well worth visiting, especially in summer.
From the railway station by the river you can take the 9 mile ride by steam train to Corwen; the return fare isn't cheap but the scenery along the route is lovely. A few minutes walk from Llangollen station is the canal, where you can take a very peaceful and leisurely 45-minute horse-drawn boat trip or a 2-hour narrow boat trip, or you can walk west along the towpath to Horseshoe Falls where water is channelled from the river to form the start of the canal itself. A short drive east is the 126ft high, 1007ft long Pontcysyllte Aquaduct which takes the canal over the River Dee; there's a towpath and railing on one side of the aquaduct but nothing on the other side, so going across in a boat gives you the sensation of gliding along in mid air - definitely not to be recommended if you don't like heights.
On an isolated hill high above Llangollen are the remains of Castell Dinas Bran (Crow Castle). On a clear day the views from there of the town, the Dee Valley and the surrounding mountains are stunning, but it's a long, very steep and strenuous walk to get to the top and not for the faint hearted; well worth it though when you do finally get there. A couple of miles outside the town is Valle Crucis Abbey, the remains of the last Cistercian monastery to be built in Wales; the site is also home to the only remaining Welsh monastic fishpond, although it was remodelled in the 18th century as a reflecting pool.
With Chirk Castle, Bala and its lake, Betws-y-Coed and Swallow Falls all within a reasonable driving distance, and coastal resorts not much further, the Llangollen area makes a good place to stay and I don't think anyone who visits will leave feeling disappointed. Photos of Llangollen and the surrounding area can be seen in my posts from Easter 2014.